The entire piece from sketches to "ink" was drawn in Adobe Illustrator on my 21" Cintiq, then I copied the line work to Photoshop, turned it into a PSD. Brought that PSD into a long abandoned product called streamline where I turn it back into a vector graphic
I do this because Streamline has an amazing "Smooth Paths" function that takes all the jitter out of my line work. So after I run that a few times I save the art as an EPS which I open back up in Photoshop and begin to color. Whew!